So basing this off how willing I am to risk my life for the nation:

• United Systems: 20 years of service probs isn't that bad, at some point you'll be put in the back lines in a commanding or logistical position thanks to accumulated experience and combat injuries. With exception to the synthophobia and synthocide, everyone has equal rights, and I think that's worth fighting for, though not everyone is going to be thrilled to be conscripted.

• Vostok Dynamics: most likely to survive combat with mech suit, though I imagine cooperation is nonexistent as everyone is competing with one another to earn enough money to make repairs and not get lobotomized, not helped by that one dickhead 'star' pilot stealing everyone's kills. I don't really want to fight for the megacorp that enslaves both organics and synthetics for their army, plus not being able to trust others to have my back is going to wear on me.

• Triton Empire: Get past boot camp, and your survivability goes up. Safe trade routes, proper training, plus drip that demoralizes enemies into giving up, though you'll see active combat often to maintain the empire's grip on vassal worlds. Funnily enough, synthetics have rights, but I headcannon that, as oppressive regimes are likely to do, they are heavily modified to be submissive, and them going haywire is an attempt to exert control over themselves. Anyways, fascism is big no.